Ancient plant oils seen fighting food
pathogens

Source of
Article:http://www.albertafarmexpress.ca/issues/ISArticle.asp?id=97611&PC=FBC&issue=03192009

Agriculture and Agri-Food Canada release

3/19/2009
6:47:00 PM

Oils derived from cinnamon and cloves do more than taste and smell good --
they can also fight food-borne diseases, such as E. coli and salmonella,
researchers are discovering.

This
natural ability of some ancient natural oils -- from geraniums, cloves, wild
oregano, cinnamon and thyme, for example -- offers promise in finding
alternatives to antibiotics used in animal feed, according to researchers at
Agriculture and Agri-Food Canada (AAFC) who are leading the study in collaboration
with the Public Health Agency of Canada and the University of Guelph.

"These
essential oils can potentially be one of many new and innovative tools for
controlling food-borne bacteria at the source, while at the same time
reducing the need for dietary antibiotics," says Dr. Joshua Gong, a
research scientist at AAFC's Guelph Food Research Centre.

Bacterial
pathogens are a common and ongoing concern in animal health and welfare as
well as food safety. For example, E. coli causes diarrhea in newly weaned
piglets, delaying growth and affecting subsequent performance and production.
Other pathogens, such as salmonella, can sometimes be found in meat products
and has the potential to be transferred to humans.

However,
consumers have expressed concerns that the use of dietary antibiotics in food
animal production may contribute to wide-spread antibiotic resistance. These
possible effects on human health have increased the demand to develop
alternatives.

Plants
contain essential oils that defend them from insects, fungi, bacteria and
other destructive invaders. Since ancient times, some of these oils have been
recognized as safe in flavourings, preservatives and over-the-counter
medicines. They have also been used in the manufacture of perfumes throughout
history.

The
first focus of AAFC's research has been testing these oils as alternatives to
dietary antibiotics in swine production. The results showed that many of the
essential oils killed the "bad" bacteria without destroying the
"good" bacteria in the intestinal tract.

The
pig infection experiments show promise. But creating the perfect blend and
concentration of essential oils and delivering it to the right section of a
pig's digestive tract continues to be a challenge. When mixed with animal
feed in a number of cases, the feed completely absorbed the antimicrobial
compound and the oil had no effect.

With
funding from Ontario Pork ($30,000, matched by AAFC through its Matching
Investment Initiative) the research team has identified a technique to encapsulate
the essential oil, thus protecting the oils from interacting with the pig
feed and delivering them to the target area.

"Through
encapsulation, the oils were rapidly released in the small intestine, which
is known to be the ideal site for maximum effect in controlling the growth of
bad bacteria and disease-causing pathogens in swine," AAFC research
scientist Dr. Qi Wang said. "However, each oil has unique properties and
may require a different carrier to help it retain its anti-microbial activity
in transit down the digestive tract."

Before
additional animal tests are performed, the team plans to look at
antimicrobial activity of the selected essential oils when mixed in various
forms (dry powder, liquid suspension) with pig feed and then subject these trials
to simulated digestion.

"Our
team is excited about the possibilities for applying this research,"
Wang said. "It's amazing when you think that something as simple as
essential oils may help animals and humans maintain digestive health. At the
same time, these essential oils may be an alternative to synthetic
antibiotics to manage food-borne pathogens."